Dwain Chambers has warned those planning on doping at the Olympic Games that they will never escape. The sprinter, who visits schools to warn children about the dangers of drug abuse, said he hoped his presence at London 2012 would make people think twice and not do something they would regret for ever.

"I hope my presence makes people think twice and not do it," he said. "I hope they never contemplate it because it really doesn't help. You may look at times and statistics but it doesn't help your life. It ruins your life and you will regret it for ever.

"It's never going to stop," Chambers said of the debate about his place in sport. "I have to get my head around the fact that this is my life and it revolves around telling other people what happened.

He told the Times: "I hope I can be used as an example. Living the lie eats you up so you can't get away with it even if you don't get caught."

Chambers, who confessed and completed his drug ban in 2005, now visits schools and has offered advice to Adam Gemili, the teenage British sprinter who won the 100 metres world junior title on Wednesday in a championship record time of 10.05sec, beating Chambers' own UK junior record in the process.

"Winning an Olympic medal would be great, but it would be immaterial compared to changing someone's life," Chambers said. "Knowing that they could have gone down the road I did, knowing the pain and the frustration I caused myself and others, knowing I could stop that would be massive."

Chambers accepts that was wrong. "World records can be done cleanly," he said. "I got worse on drugs. It did not help me in any capacity. It made me a very unsociable person and ruined my career and the image of the sport. I hate to think I caused that. That is guilt."